RFR: Upstream merge from jdk/jdk

[Aleksey Shipilev]

On 1/8/19 5:37 PM, Roman Kennke wrote:
>>> First merge from upstream in new world order. Merge was 0 conflict and
>>> trivial, everything builds+ runs just fine. It merges up to tag jdk-13+2
>>>
>>> http://cr.openjdk.java.net/~rkennke/upstream-jdk13-merge-2019-01-08/outgoing.txt
>>>
>>> Testing: hotspot_gc_shenandoah
>>>
>>> Ok?
>>
>> OK, but sh/jdk12 should fork first.
> 
> I don't think this is necessary. sh/jdk12 will be forked from jdk/jdk12
> which has (almost) the same Shenandoah as we have in sh/jdk. Shenandoah
> itself is not yet moving in any branch.

So... sh/jdk12 would be special: it would not have the "[backport]" changesets that are in every
other sh/jdk* repository, including the sh/jdk itself. This can complicate maintenance work? I'd
rather fork sh/jdk12 from current sh/jdk. This would also check we haven't missed anything in jdk/jdk12.

-Aleksey